Method for operating a wind power installation, wind power installation and wind farm

Abstract

The present disclosure relates to a method for operating a wind power installation, in particular for identifying unusual oscillation events, and an associated wind power installation and a wind farm. The method comprises the steps of: providing a parametrized limit for a value of an observed oscillation of a component of the wind power installation; determining a current limit from the parametrized limit taking account of at least one current ambient parameter, in particular an ambient parameter that is indicative for the current incident flow; determining a current value of the observed oscillation of the component; comparing the current value of the observed oscillation of the component with the current limit; and operating the wind power installation on the basis of the result of the comparison.

1 . A method for operating a wind power installation, the method comprising:
 providing a parametrized limit for a value of an observed oscillation of a component of the wind power installation, the component being at least one of a tower head, a rotor blade, a generator, and a rotor,   determining a current limit from the parametrized limit taking into account of at least one current ambient parameter,   determining a current value of the observed oscillation of the component,   comparing the current value of the observed oscillation of the component with the current limit, and   operating the wind power installation based on the comparison.   
     
     
         2 . The method according to  claim 1 , wherein the current value of the observed oscillation is a value that characterizes the observed oscillation or a value derived from the observed oscillation, including at least one of an acceleration, a maximum oscillation deflection, and a frequency component. 
     
     
         3 . The method according to  claim 1 , wherein the ambient parameter comprises a wind speed, the wind speed being measured or determined by a wind estimator from a current operating point of the wind power installation. 
     
     
         4 . The method according to  claim 3 , wherein the wind speed has a reference time period that is one of less than 1 minute, between 10 and 30 seconds, or less than 10 seconds. 
     
     
         5 . The method according to  claim 1 , further comprising measuring the value of the observed oscillation on the component. 
     
     
         6 . The method according to  claim 5 , wherein the measuring is carried out using at least one of an acceleration sensor, a gyroscope, an incremental encoder, a strain measurement, an optical sensor and a power measuring device. 
     
     
         7 . The method according to  claim 1 , wherein the value of the observed oscillation is derived from measurements on a component of the wind power installation that differs from the observed component. 
     
     
         8 . The method according to  claim 7 , wherein the observed component is the rotor of the wind power installation and a current value of the oscillation of the rotational speed of the rotor is derived from a generator current. 
     
     
         9 . The method according to  claim 7 , wherein the component of the wind power installation is one or more of the following components:
 the tower head, with a tower head acceleration being observed,   the rotor blade, with oscillations of a pitch angle and/or swivel load of the rotor blade being observed,   the generator, with oscillations of a generated power of the generator being observed, and   the rotor, with oscillations of a rotational speed of the rotor being observed.   
     
     
         10 . The method according to  claim 9 , further comprising observing a tower head acceleration of the tower head, wherein comparing the tower head acceleration with the current limit comprises:
 filtering using a low-pass filtering of the tower head acceleration to observe components of the tower head acceleration of no more than 0.8 Hz, and/or   determining an extremal point of the tower head acceleration, and comparing the extremal point of the tower head acceleration with the limit, and/or   determining a mean amplitude of the tower head acceleration, and comparing the mean amplitude with the limit.   
     
     
         11 . The method according to  claim 9 , further comprising observing oscillations of a pitch angle of the rotor blade, wherein comparing the current oscillation of the pitch angle with the current limit comprises:
 filtering the current oscillation of the pitch angle to eliminate wind-excited oscillations, and/or   making a distinction between singular events, singular overshoots of the current limit, or prolonged events.   
     
     
         12 . The method according to  claim 9 , further comprising observing oscillations of a swivel load of the rotor blade, and wherein comparing the current oscillation of the swivel load with the current limit comprises a compensation of an oscillation contribution whose frequency corresponds to the rotor rotation and corresponds in terms of absolute value to the gravitational contribution. 
     
     
         13 . The method according to  claim 9 , further comprising observing oscillations of a power generated by the generator, and wherein comparing the current oscillations in the generated power with the current limit comprises:
 filtering the generated power to eliminate wind-excited oscillations, and/or compensating power changes induced by controlling the wind power installation.   
     
     
         14 . The method according to  claim 9 , further comprising observing oscillations of a rotational speed of the rotor, and wherein comparing the current rotational speed of the rotor with the current limit comprises filtering the observed rotational speed to eliminate wind-excited oscillations. 
     
     
         15 . The method according to  claim 1 , further comprising:
 determining an expected operating load of the wind power installation during normal operation,   comparing the expected operating load of the wind power installation with a measured actual load of the wind power installation and   adjusting the parametrized limit based on the comparison.   
     
     
         16 . The method according to  claim 15 , wherein the adjustment of the parametrized limit comprises:
 increasing the parametrized limit by a predetermined increase factor when the parametrized limit has been exceeded, and/or   reducing the parametrized limit by a predetermined reduction factor when the parametrized limit has not been exceeded over a predetermined period of time.   
     
     
         17 . The method according to  claim 1 , wherein the operating the wind power installation based on the comparison comprises:
 detecting an unusual oscillation event when the current value of the observed oscillation overshoots or undershoots the current limit, and   communicating the detected unusual oscillation event by way of SCADA.   
     
     
         18 . The method according to  claim 1 , wherein the at least one current ambient parameter is an ambient parameter that is indicative for the current incident flow. 
     
     
         19 . A wind power installation comprising a controller, wherein the controller is configured to implement the method according to  claim 1 . 
     
     
         20 . A wind farm comprising a plurality of wind power installations according to  claim 19 .